1. Technical Field
The present invention relates to a projector.
2. Related Art
There is a known configuration having a diaphragm provided in an illumination system for improvement in contrast. For example, in the projector described in JP-A-2004-361856, a diaphragm is disposed on the light incident side of a light valve and blocks obliquely incident light that lowers the contrast. To display a full-color image, a diaphragm may be provided for each of three light valves for RGB light fluxes.
In a three-panel projector, light outputted from a white light source is divided into three color light fluxes or RGB light fluxes, which are then guided to three light valves for the RGB light fluxes. When a diaphragm is disposed on the light incident side of each of the light valves, it is preferable that the sizes of the diaphragms are set to be equal to one another so that the white balance does not deteriorate.
On the other hand, a projector using a combination of a solid-state light source and a phosphor has been developed in recent years. As a projector of this type, there is a known projector including a first light source unit that is a combination of a solid-state light source and a phosphor and a second light source unit that is a combination of a solid-state light source and a diffusion member. For example, the first light source unit produces R and G light fluxes, and the second light source unit produces a B light flux. Then, thus produced light fluxes are separated from each other and guided to three light valves for the RGB light fluxes.
In a projector of this type as well, diaphragms can be used to improve contrast. However, the present inventor has conducted a study and found that setting the sizes of the RGB diaphragms to be equal to one another as in a typical three-panel projector undesirably results in a bluish displayed image and the white balance greatly deteriorates.